The Concentration and Biomagnification of Pcbs and Pbdes Across Four Trophic Levels in a Marine Food Web

Madgett, Alethea S.; Yates, Kyari; Webster, Lynda; McKenzie, Craig; Brownlow, Andrew; Moffat, Colin F.

doi:10.2139/ssrn.4058810

Cited by 2 publications

(3 citation statements)

References 59 publications

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“…In comparison to the multiple stable isotope data, the fatty acid compositions of food sources are generally considered to be significantly different et al, 2009;Madgett et al, 2019). In our study, all food sources were rich in saturated fatty acids (61%-77%), especially 16:0, which was similar to the research results in other seagrass beds (Crawley et al, 2009;Park et al, 2013).…”

Section: B a Figuresupporting

confidence: 86%

Identification of food sources in tropical seagrass bed food web using triple stable isotopes and fatty acid signatures

et al. 2023

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Identifying the trophic role of primary producers is the basis of assessing seagrass bed functions but remains difficult due to the underdetermined analysis method. Here, we analyzed the multiple isotopes (δ13C, δ15N, and δ34S values) and fatty acid markers of food sources and macrobenthos in a tropical seagrass bed in summer and winter, and tried to combine these indicators to resolve the limitation of δ13C and δ15N values analysis. We found that the δ13C and δ15N values of epiphytes were like that of seagrass and macroalgae, while the δ34S values of epiphytes and macroalgae were significantly different, and the dominant unsaturated Fatty acid markers of seagrass (18:2n6c and 18:3n3) and epiphytes (16:1n7) were obviously different. These results suggest that the combination of multiple isotopes and Fatty acid markers can effectively distinguish the complex food source. In addition, we also found that multiple isotopes were more suitable to identify the food sources of polychaetes and snails with simple diets, fatty acids were more suitable to identify the food sources of crustaceans with complex diets, but their combination is essential in identifying the diets of macrobenthos since the wide range of isotopic values for omnivores crustaceans and the Fatty acid markers transformation during snails and polychaetes assimilation might mislead us when only isotopes or Fatty acid markers were used. Our findings suggest that in tropical seagrass beds, using multiple isotopes and fatty acid markers together can help reduce the uncertainty caused by single markers variation and thus strengthen the separation of food sources and the diets of different consumer species.

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Section: B a Figuresupporting

confidence: 86%

Identification of food sources in tropical seagrass bed food web using triple stable isotopes and fatty acid signatures

et al. 2023

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“…Northeast Atlantic fish, cephalopod, and crustacean muscle d 13 C and d 15 N (n = 1964 specimens) were compiled to provide additional context for interpreting dolphin diet (Das et al, 2003;Schaal et al, 2010;Chouvelon et al, 2012;Varela et al, 2013;Jennings and Cogan, 2015;Louzao et al, 2017;Madgett et al, 2019; 2; Figure S2 and Supplementary Material Table 3). Prey muscle d 13 C cor has been normalised for lipid content following Post et al (2007), and Suess Effect-corrected (0.015 ‰ per year) to 2021 (Keeling, 1979;Sonnerup et al, 1999).…”

Section: Dietary Comparison Of Prey D 13 C and D 15 Nmentioning

confidence: 99%

“…The spatial distribution of marine habitats (latitude and water depth) also has a strong influence on primary producer d 13 C, the effects of which are carried up the food chain by consumers (Magozzi et al, 2017;Espinasse et al, 2022). Carbon and nitrogen stable isotope compositions of consumer proteinaceous tissues (such as skin) are directly correlated with diet, providing proxy evidence of nutrient flow within a marine ecosystem as well as trophic position (Madgett et al, 2019;Parzanini et al, 2019;MacKenzie et al, 2022). The trophic enrichment factor between diet (prey muscle) and dolphin skin is approximately 1 ‰ for d 13 C and 1.5 ‰ for d 15 N (Browning et al, 2014;Gimeńez et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Stable isotope ecology and interspecific dietary overlap among dolphins in the Northeast Atlantic

et al. 2023

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Dolphins are mobile apex marine predators. Over the past three decades, warm-water adapted dolphin species (short-beaked common and striped) have expanded their ranges northward and become increasingly abundant in British waters. Meanwhile, cold-water adapted dolphins (white-beaked and Atlantic white-sided) abundance trends are decreasing, with evidence of the distribution of white-beaked dolphins shifting from southern to northern British waters. These trends are particularly evident in Scottish waters and ocean warming may be a contributing factor. This mobility increases the likelihood of interspecific dietary overlap for prey among dolphin species previously separated by latitude and thermal gradients. Foraging success is critical to both individual animal health and overall population resilience. However, the degree of dietary overlap and plasticity among these species in the Northeast Atlantic is unknown. Here, we characterise recent (2015-2021) interspecific isotopic niche and niche overlap among six small and medium-sized delphinid species co-occurring in Scottish waters, using skin stable isotope composition (δ13C and δ15N), combined with stomach content records and prey δ13C and δ15N compiled from the literature. Cold-water adapted white-beaked dolphin have a smaller core isotopic niche and lower dietary plasticity than the generalist short-beaked common dolphin. Striped dolphin isotopic niche displayed no interspecific overlap, however short-beaked common dolphin isotopic niche overlapped with white-beaked dolphin by 30% and Atlantic white-sided dolphin by 7%. Increasing abundance of short-beaked common dolphin in British waters could create competition for cold-water adapted dolphin species as a significant portion of their diets comprise the same size Gadiformes and high energy density pelagic schooling fish. These priority prey species are also a valuable component of the local and global fishing industry. Competition for prey from both ecological and anthropogenic sources should be considered when assessing cumulative stressors acting on cold-water adapted dolphin populations with projected decline in available habitat as ocean temperatures continue to rise.

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The Concentration and Biomagnification of Pcbs and Pbdes Across Four Trophic Levels in a Marine Food Web

Cited by 2 publications

References 59 publications

Identification of food sources in tropical seagrass bed food web using triple stable isotopes and fatty acid signatures

Identification of food sources in tropical seagrass bed food web using triple stable isotopes and fatty acid signatures

Stable isotope ecology and interspecific dietary overlap among dolphins in the Northeast Atlantic

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